This project will provide a test of four antigens on adult and juvenile Macacas on Cayo Santiago, Puerto Rico. The initial statistical problem was to determine the percent of positive antibody titers that could be determined from the adult sample for whom blood sera are presently available, and the number of juveniles that should be sampled. The entire monkey colony on Cayo Santiago will have been trapped and bled by January of l985, and the serological analysis for the four antigens completed by late l985.